Increased Efficiency of Solar Panels
Solar panels may compete with green roofs for use of the roof space, but have been found to increase the energy efficiency of green roofs.
Research has shown that green roofs and solar panels are complementary. Photovoltaic cells over a green roof have a higher voltage output and the green roof vegetation below the cells is more diverse as conditions are less stressful for plant growth.
Research carried out in Berlin has indicated that the cells over a green roof were found to have a 6% higher output compared to cells on a bitumen roof.
This is because the output of photovoltaic cells is higher at low temperatures and suggests that the extra productivity can help offset the cost of a green roof.